Welded structure and method of assembling same



`lune 2l, 1949. E, A` PARMANN 2,473,660

WELDED STRUCTURE AND METHOD OF ASSEMBLING SAME Filed Feb. 12, 194'7v INVEN TOR.

Annen/5545*.

Patented June 21, 1949 WELDEDS STRUCTURE 'AND'METHOD '0F ASSEMBLING SAMEfEjgwin A. Parmann, Batavia, ,'Ill., assigner `to Furnas ElectricCompany, Batavia, Ill., `a Vcorporation of Illinois ApplicationF-ebruary12, 19,47,-Ser ial,:No.,$28,024

5 Claims.

. Mygpresent inventionrelates generally to im- .provementsfin the lartoffabrication by welding, and relates more particularly vtoimprovementsin ithe construction and Amethod of assembling tubular membershavng endviiange-like elements firmly .associated therewith.

v.A primaryobjectof the .present, invention is to fprovideanin lprovefdwelded structure which is simple ,and extremely durable in construction,andv animprovedmethod. of producing the, same in, a., highlyetlicientand practical manner.

"In the V commercial manufacture lof switches such `as shown,for,example in U. S. Patent No. 2,193,126,` granted,March 12,1940, toWilliam C. Furnas considerable diiculty hasheretofore been encountered'Ainrsatisfactorily attaching the fluid ypressure supply pipe, or thethreaded nut for receivngsuch pipe, to the'lower plate of the diaphragmenclosure. It'has heretofore been customary 4tojfastentheseparts'together by brazing V and/or riveting.but such priorzmethodswere not Yentirely satisfactory because theyy were expensive andimpractical from a production standpoint ,andtheresultantassemblageswere not uniformly secure and suflicientlyintegrally united.Various attempts; have also heretoforebeenmade at welding theso-called"air nu ""for receiving the fluid pressure supply pipe to thediaphragmenclosure jgplate, but'these ,attempts have also beenunsuccessfulfor various reasons. 'When the parts are-L united byordinary known welding methods, it 'hasgbeenfoundthat theresultant`welds are `like wise;not'uniformly'secure, and furthermore durin g theusual welding. process themolten metal is caused'to sputter and `splashinto .the central. 4 f

'aperture vof the diaphragm enclosure plate and into vthe screw-threadedair nut, thereby necessitatingA additional subsequent machining.

Itisithereforea more specic ,object of the 1present vinvention toVprovide lan improved diaphragm enclosure., plate andair nut assemblage`-w hich is exceedingly and uniformly strong vand 1- secure and'whichmay beproducedin large quantities and at low cost by welding inAaccordance with an improved method.

Anotherspecic object of thisinvention is to ,provide an improved articleof manufacture-com- ',ifprising, a member having a bore provided with aconstriction'formedby a, second member integrally united therewith inanovel and efficient manner.

Another specific object of `my invention is to ,provide an improvedvmethodof weldingv an end flange-like element to a member having a `bore``to rmly unite the sameand. provide, an extremely 2 durable.assemblage. without .causing lundesirable Hmetal deposits within the,bore duringthe welding ,.operation.

.An 1additionalspecic v,object of my present invention is to provide. animproved. diaphragm enclosure plate and.airnutassemblagefor pres- .sureactuated switches .which may be readily commerciallyproduced inahighlypractical manner Aby the useof `projection Welding in accordance with-.an kimprmzed method.

vAfurther specicobject ofthe present invention is .to provide animproved method of producirlga strongdurableand highly efficient unitarydiaphragm enclosure plate and air nut assemblage forpressure switcheswithr a minimum number. of simple operations.

yStill another specific objecto ,the present invention vis to provide animproved method of ,forming a constricted passageway at the end of atubularmember while simultaneously Ipermanently uniting aflange-likeelement to the same end of the tubular member Vby Welding. I

'These and otherspecic lobjects and advanytages of the ,presentinventionwill be apparent fromthe following detailed description.

Aclear, conception of the features constituting my present inprovement,and of the construction and use of'typical articles embodying theinvention andproduced in accordance with my improved method, maybe hadbyreferring to the drawing accompanying andV forming a part of thisspecication, wherein like reference characvters designate the same or`similar parts in the several views.

iFig. 1 is an exploded central transverse crosssectional view oftypicalparts prior to assembly thereof in accordance with my invention;

Fig. 2"is a similar transverse cross-section of the same parts ^inposition y between fragments of .theA welding electrodes just V.priorV,to .application f of welding current;

Fig 3 is .another vsimilar transverse` cross-fseetion ofthe -parts atthe lmoment ofcompletion of the welding operation;

'.Fig. 41s. a somewhat reducedtransverse lcentral .section "through-afinally completed welded asl.semblagm and Fig. .5,.is a similarly`reduced -bottom View of the ...completed unit.

While the inventon'vhas. been shown and described .hereinasappliedto andAembodied in a Atypical diaphragmenclosure plate -and air nut.assemblage for pressure actuated switches, it is not ,my desire vorAintention lto thereby unnecessarily .restrict thescopeor utilitythereof, since 3 the improvement may obviously be applied to andutilized with other types of structures.

Referring to the drawing, the improved assemblage, shown therein by wayof illustration, comprises in general, a tubular member or nut I havingthe bore II thereof provided with screw threads I2; a plate member ordisk I3 of somewhat lesser width or diameter than the member I0 but ofgreater diameter than the bore II disposed at an end of the tubularmember I0, the plate member I3 having an aperture or central bore i4 oflesser diameter than the bore II to form a constricted passage at theend thereof; and a Ilange-like member or diaphragm enclosure plate I5surrounding the plate or disk I3 and integrally united by theapplication of welding heat and pressure to the adjacent end of thetubular member I0 beyond the outer periphery of the plate I 3, a portion.of the flange member I5 adjacent to and immediately surrounding theplate I 3 being forced inwardly over the outer peripheral edge of theplate I3 as at I6 during the pressure Welding operation to firmly andsecurely unite the tubular member I D and the plate member I3 entirelyabout the bore II so as to provide an integral rigid assemblage.

In the present typical assemblage, the flange member I5 is what iscommonly known as a diaphragm enclosure plate and as such it is adaptedto be secured to the lower end of a pressure switch casing in the mannershown in Patent No. 2,193,126, hereinabove referred to; and theinternally threaded tubular member Ill is known to those skilled in theart as an air nut and forms the threaded connection for the fluidpressure supply pipe, also shown in Patent No. 2,193,126.

In assembling and producing the improved articles in accordance with mypresent method, the member I5 is nrst provided with a central throughopening or bore I'I of such size as to permit relatively snug receptionof the plate or disk I3 therein, and with a relatively sharp and narrowdepending annular ridge or projection I8 entirely surroundingr theopening I1. The parts are then juxtaposed as in Fig. 2 with the disk orwasher I3 received in the bore Il of the member I5 and surrounded by thedepending portion I8, the disk I3 and the annular knifedike edge of theprojection I8 being placed directly against an end of the tubular memberIG. The tubular member or nut Itl is then caused to contact a stationaryelectrode IS, after which a cylindrical movable electrode 2Q is broughtagainst the flange member or enclosure plate I5; and with the parts inposition between the stationary electrode I9 and the movable electrode20, as above described and as clearly shown in Fig. 2, the weldingcurrent is turned on and simultaneously with the flow of welding currentfrom the movable electrode through the parts to the stationary electrodeI9, pressure is applied to the member I5 by the movable electrode 20.During this welding operation under pressure, the welding current flowsas indicated by the arrows in Fig. 3, the major ow of current being inthe region beyond the outer periphery of the disk I3 since there is amore direct path for flow of current through this region; and as thisflow proceeds and pressure is applied, the projection I8 of the flangemember I5 melts and a substantial portion of this metal is caused toflow inwardly over the outer peripheral edge of the disk I3 as at I6 inFigs. 3 and 4, and this metal portion I6 is, of course, fused to someextent by the welding current to the disk I 3.

It is to be noted that although in actual com- 4 mercial practice, theair nut IIJ and the enclosure plate I5 are formed of steel and the diskor washer I3 is formed of stainless steel which has a high electricalresistance, these parts may however be formed of other suitablematerials; and satisfactory assemblages have in fact been produced whichembody the use of disks I3 of phosphor bronze which has a low electricalresistance and of mica which is an insulator. It should, of course, beunderstood that the parts are cleaned and otherwise prepared in thecustomary manner prior to the welding operation, and the electrodes I3,2D are of the usual type used in projection welding. Upon completion,the improved devices, assembled in accordance with the new method, areextremely strong and durable with the enclosure plate I5 of each unitintegrally united by the welding operation to the air nut It entirelyaround the periphery of the disk I3.

From the foregoing detailed description, it is apparent that the presentinvention provides an improved welded structure which is simple andextremely durable in construction, and an improved method of producingthe same in a highly eiiicient and practical manner. During the weldingoperation, the current flows through the parts as indicated, melting theannular projection I3 which is caused by pressure to overlap the disk I3entirely around its outer peripheral edge, and due to the resistance ofthe disk I3 and/or the resistance between the metal surfaces of theparts, coupled with the fact that there is a more direct path for flowof current through the region beyond the outer periphery of the disk I3,considerably more heat is produced along the outer surface of the airnut I0 and an excellent and uniform union by welding between the membersI0 and I5 results. Furthermore, during the welding operation, the moltenmetal is prevented from spilling or flowing into the bore II of themember I0 and the internal threads I2 thereof are thus protected fromdamage during assembly. It should also be noted that the presentinvention not only provides an improved practical and simple method ofrigidly uniting' an end Hangelike member to a tubular element by weldingand without causing undesirable metal deposits in the bore of thetubular member during production, but it also contemplates simultaneousprovision of a constricted passa-ge at the end of the tubular member.Diaphragm enclosure plate and air nut assemblages commercially producedin accordance with the improved method have proven to be strong, durableand highly efficient and a minimum number of operations in such methodhas enabled quantity production of these assemblages at reduced cost.

It should be understood that it is not desired or intended to limit thisinvention to the exact details of construction or to the precise methodof assembling or mode of utilizing the improved assemblages, hereinshown and described, for various modications Within the scope of theappended claims, may occur to persons skilled in the art to which thisinvention pertains.

I claim:

l. An article of manufacture comprising, a member having a bore, aplate-like meneer of lesser width than that of said lrst-mentionedmember but wider than said bore, said plate me., ber being disposed nearan end of said :rst m-nber and having an aperture of lesser diameterthan said bore to form a constricted passage, and a flange-like membersurrounding said plate member and being integrally united by welding aportion thereof exten outer edge of said plate said plate member to saidvide an integral structure.

2. An article oi manufacture comprising, a bular member, a plate-likemember of lesser Width than that of said tubular member but wider thanthe bore thereof, plate member being disposed at an extreme end oi saidtubular member and having an aperture cf lesser diameter than the borethereof to form a constricted passage, and a flange-like membersurrounding said plate member and being integrally united by welding tothe extreme end of said tubular member entirely around said platemember, said flange member having a portion thereof extending inwardlyover the outer edge of said plate member to securely unite said platemember to said tubular member and provide an integral structure.

3. An article of manufacture comprising, a tubular member, a disk oflesser diameter than said tubular member but of greater diameter thanthe bore thereof, said disk being disposed directu ly against an end ofsaid tubular member and having a central opening therethrough of lesserdiameter than the bore thereof to form a constricted passage, and aflange-like element having a bore for snugly receiving and embracingsaid disk and being integrally united to said tubular member beyond theperiphery of said disk by welding, said flange element having anintegral portion thereof adjacent its bore overlapping the entire outerperipheral edge of said disk to securely unite said disk to said tubularmember and provide an integral structure.

4. The method of producing a tubular member having an integral nange-lkeelement at an end thereof, which comprises, forming a relatively flatmember of lesser Width than the tubular member but Wider than the borethereof with an aperture of smaller diameter than the bore of saidtubular member, providing a bore in the harige-like element of a sizesuch as to permit reception of said flat member and with a ridge ofexcess material surrounding said bore of the flange-like element,thereafter positioning the parts so that the at member is receivedWithin the bore of said flange element and with both the flat member andthe ridged portion of the flange element resting directly against an endor said tubular member, and inally uniting the parts by vfielding andsimultaneously applying pressure causing the ridged portion of theflange element to r elt and overlap the outer edge of said flat mei anddirectly uniting said tubular member and said 'dange element utvfardlybeT ond said member.

5. The method of producing a tubular me1nber having an integralflange-like element at an end thereof, which comprises, forming a diskof lesser diameter than the tubular member but of greater diameter thanthe bore thereof with a central aperture oi smaller diameter than thebore of said tubular member, providing a bore in the angelike element ofslightly larger diameter than the diameter of said disk and with anannular depending relatively narrow ridge of eX- cess material imliediately adjacent to and entirely surrounding said bore of the flangeelement, thereafter placing said disk within the bore of said :flangeelement and positioning the parts so the disk and the surroundingclepending ridge portion of the flange element are both resting directlyagainst an end oi said tubular mber, and iinally uniting the parts byunder pressure to cause the ridged portion of the ilange element to meltand be forced over the outer peripheral edge of Said disk and directlyuniting said tubular member and said ilange element beyond the outerperiphery of said disk.

EDVJIN A. PART-KANN.

REFERENCES CITED The following references are of record in the nle ofthis patent:

UNITED STATES PATENTS Number Name Date 703,657 Horn -i July 1, 19021,604,531 Murray Oct. 26, 1926 1,865,926 Laing July 5, 1932 2,121,984Rieger June 28, 1938 2,202,405 Smith May 28, 1940 2,273,306 Woods Feb.17, 1942 2,372,772 Ellis et al. Apr. 3, 1945

